Defensive lineman Jarron Gilbert, the 2009 third-round pick from San Jose State, is running out of time to convince coaches that he deserves a spot on the Bears' 53-man roster.

Gilbert missed preseason Game 2 with a neck injury, and he didn't do much in the opener or in training camp to set himself apart at a position that features quantity and quality.

"He's one of the guys fighting for a spot," coach Lovie Smith said. "He needs to get out there on the field, first, and then make some plays. It's as simple as that. The guys that have the opportunity to play (Saturday night), we'll put them out on the field and let them show that they belong on the 53-man roster, or even the 61 (53 plus eight practice squad players)."

The 6-foot-5, 285-pound Gilbert made brief appearances in just four games last season and did not have a tackle.

Do it all: Julius Peppers' pass-rush prowess is common knowledge. He's hit double figures in sacks in six of his eight NFL seasons.

But Peppers demonstrated his dominance against the run in last week's game when he had 2 huge tackles near the line of scrimmage with the Raiders inside the Bears' 5-yard line.

"He's about as complete of a defensive end as you'll see," coach Lovie Smith said. "A 300-pound man with DB-type speed, plays with leverage, plays the run, plays the pass, all situations. We have a lot of things in store as far as what we're going to do with him this year. He plays as hard as anyone, pursues ... should I stop? We could keep going for a while.

"He's a scholarship player that we're going to keep around here for a while."

Waiting game: Coach Lovie Smith said 38-year-old quarterback Todd Collins, who was signed Monday, will not play in Saturday night's third preseason game.

With Jay Cutler and the first-team offense slated to play into the third quarter, it's expected that rookie Dan LeFevour and Matt Gutierrez will divide playing time the remainder of the game. It would be the Bears debut for Gutierrez, who was signed Aug. 18 but did not play in last week's preseason game against the Raiders.

Taking a pass: Linebacker Brian Urlacher (calf) did not practice Thursday, although he did some running on the side. He will not play Saturday. Others out for the Cardinals game are quarterback Caleb Hanie (shoulder), wide receiver Earl Bennett (hamstring), safety Craig Steltz (ankle) and safety Major Wright (finger), who has been practicing but is not yet cleared for contact.